I. Field of the Invention
This invention relates to fluid conductors and, in particular, to a fluid conductor connector assembly which incorporates a dielectric insulator assembly within the female connector to reduce corrosion between dissimilar metal connections.
II. Description of the Prior Art
Connectors for fluid systems such as hot water heaters often incorporate components made of dissimilar metals. One example is the copper tubing used in many connector assemblies and a galvanized male nipple. As water flows across these components an electric current on the order of 1-2 milliamps is created depending upon the temperature and condition of the water. This galvanic action causes corrosion which can deteriorate the connector assembly and clog flow paths through the water system.
Various modifications have been made to such water systems in an attempt to reduce or eliminate galvanic corrosion. Since such corrosion results from the use of dissimilar metal components the most obvious alternative is to utilize similar materials throughout the system. However, this may not always be practical particularly when parts are added to or replaced in the existing system. Alternatively, since the corrosion is a result of the electric current flowing across the dissimilar metal components, insulators have been incorporated in the galvanized male connector or nipple which prevents contact with the tubing connected thereto. Such insulators are in the form of a sleeve with a radial flange. The sleeve portion extends into the flow passageway of the nipple while the flange sits at the opening to prevent full insertion. In the prior known sleeves the flange extends beyond the periphery of the nipple in order to create a sealing engagement between the threads of the connectors. One prior known sleeve includes a secondary flange beyond the first flange which is deformably crimped between the threads upon connection. These insulator sleeves incorporated into such male connectors provide sufficient isolation to reduce galvanic corrosion. However, the sleeves have a tendency to fall out of the connector since they are dependent upon a friction fit with the interior wall of the connector. As a result, the sleeves were made longer than necessary or incorporated crimping means to maintain their position within the connector. Moreover, it has been found that in most cases it is the tubing connector which is replaced. If the galvanized nipple has not been previously provided with an insulator sleeve because identical materials were being used, replacement of the connector can cause galvanic corrosion.
The one-piece dielectric insulator sleeve disclosed in U.S. Pat. No. 5,169,180 was expected to provide a compromise of structural properties to prevent galvanic corrosion. The flange portion was intended to be soft enough to act as a seal while the tubular body needed to be stiff enough to stay tight against the wall of the connector hose and out of the flow path of the water. However, this construction compromised the operation of the sleeve.
The present invention overcomes the disadvantages of the prior known fluid connector assemblies by providing a connector with an insulator assembly incorporated into the female connector which reduces corrosion while also acting as a sealing washer for the connection.
The fluid conducting connector assembly according to the present invention includes a tubular conductor or pipe and at least one internally threaded female connector attached to the end of the tubing. Typically, the connector is of the swivel type which allows rotation for connection without rotating the tubing. The female connector is adapted to threadably engage a male nipple upon assembly of the fluid system.
In order to reduce corrosion, an insulator is incorporated into the end of the fluid conducting connector. The insulator assembly generally includes a dielectric sleeve which extends partially into the connector hose and a sealing washer engaging the sleeve. The sleeve has a tubular body closely matching the inner diameter of the connector hose in order to dielectrically separate the connection. An outer end of the sleeve has an outwardly disposed peripheral flange. Preferably, the flange has a conical or frusto-conical cross-sectional configuration in order to sealingly cooperate with the washer. The washer may have a conventional rectangular cross-sectional configuration or a frusto-conical cross-sectional configuration in order to cooperate with the peripheral flange of the sleeve and sealingly engage the female connector to prevent fluid leakage. Upon insertion of both components, the sealing washer will capture the insulator flange against a shoulder of the connector thereby maintaining the sleeve with the connector. In order to optimize the properties of both components, the washer is preferably made of synthetic rubber which has improved sealing properties and the sleeve is preferably made of a glass filled polypropylene.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.